Specification :

1. Description:
Sodium pyrosulfite( Na2S2O5 )

2. Properties:
white or light yellow crystal powder, a strong smell of sulfur dioxide, relative density is 1.4, easy to dissolve in water and glycerin, water solution. It has acidity, and its solubility will become large while raising the temperature and is less to dissolve in ethanol.

3.Packing:
25kgs/ Bag 25mts/ 20' FCL

4. Specification:
Specification For Food Grade and Industry Grade :
 
Item Quality Index
Food Grade Industry Grade
Purity ( As Na2S2O5) 98.0% min 96.0% min
Sulfur Dioxide( SO2) 65.0% min 65.0% min
Arsenic ( As ) 0.0002% max -
Heavy metals ( As Pb ) 0.0005% max -
Selenium ( Se ) 0.0005% max -
Iron ( Fe) 0.001% max 0.002% max
Water insoluble 0.02% max 0.05% max
PH value : 4.0-4.8 4.0-4.8
Remark : Conformed with FCC V and E 223 Standard
 
Specification for Pharmaceutical Grade and Photo Grade   
Item Quality Index
Pharmaceutical Grade Photo Grade
Purity ( As Na2S2O5) 98.0% min 98.0% min
Sulfur Dioxide( SO2) 65.0% min 65.0% min
Thiosulphate ( As S2O3) : 0.05 % max 0.05% max
Chloride ( As CL-) : 30 ppm max 50ppm max
Arsenic ( As ) : 1ppm max 1ppm  max
Lead ( Pb ) : 1 ppm max 2ppm max
Copper ( Cu) : 1 ppm max 1ppm max
Iron ( Fe ) : 5 ppm max 5ppm max
Mercury ( Hg) : 0.1ppm max 1ppm max
Chromium ( Cr) : 1 ppm max -
Selenium ( Se ) : 1 ppm max 5ppm max
Zinc ( Zn) 1 ppm max 1ppm max
Cadmium ( Cd ) 1ppm max -
Nickel ( Ni) 1ppm max -
Na2SO3  + Na2SO4 1.5% max -
PH value : 4.0-4.8 4.0-4.8
Remark : Conformed with USP standard

5. Handling and Storage:
External polypropylene woven bag, polyethylene plastic bag lining.

6. Applications:

1. Dyeing mordant, dechlorinating agent for washed fabric, medical deoxidizer and sulfonating agent, bone black for bamboo, wood and paper fiber, non-ferrous mineral separation agent, waste water disposing agent, rubber coagulator.

2. Food-grade sodium metabisulfite. Main purposes: . Bleaching agent( for sugar, pastry, dried slices of tender bamboo shoots, etc ) , loosening agent( for bread, biscuit, etc ) , corrosion protection antiseptic( fruit juice, can, etc ) , antioxidant( for lily flower, sea food, fruit, vetegable, etc ) .